Streptozotocin-induced hyperglycaemic mice are susceptible to invasive enteric bacterial infection.

Diabetes mellitus and diarrhea are becoming increasingly burdensome worldwide, particularly in developing countries such as India. Diabetic patients are susceptible to infection with pathogenic bacteria, particularly those causing invasive enteric infections. In this study, we observed changes in the pathophysiological features of mice with streptozotocin-induced hyperglycemia. In our experiments, both hyperglycemic and control mice were infected with pathogenic enteric bacteria-non-typhoidal Salmonella, Shigella flexneri, or Vibrio parahaemolyticus. Morbidity, mortality, and bacterial load were all higher in the diabetic mice than in the control mice, and the phagocytic and bactericidal activities of peritoneal macrophages isolated from hyperglycemic mice were lower than they were in the controls. We hypothesize that hyperglycemia leads to a downregulation of the innate immune response, which in turn increases vulnerability to enteric bacterial infection.